I. Field
The following description relates generally to wireless communication, and particularly to cell acquisition and sequences for acquiring cell information employing synchronization channels and a broadcast channel.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, data, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., bandwidth and transmit power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. But regardless the peculiarities of the many available wireless communication systems, in each of these systems a terminal or wireless device upon switching on must perform cell acquisition or cell search in order to become operational. Cell acquisition is the procedure by which a terminal acquires time and frequency synchronization with the network, cell identification, and additional identification of system information critical to operation such as system bandwidth and antenna configuration of cell transmitter.
In a wireless system like third generation long term evolution (3G LTE), or evolution universal terrestrial radio access (E-UTRA), advantageous features for enhanced communication performance such as presence of a cyclic prefix to mitigate inter-symbol interference in orthogonal frequency division multiplexing, and downlink system bandwidth versatility (e.g., a 3G LTE system can be capable of multiple BWs: 1.25 MHz, 1.6 MHz, 2.5 MHz, 5 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz) have led to unique complexities during initial cell acquisition. Besides time synchronization; namely, detection of symbol boundary; 0.5 ms slot boundary; 1 ms sub-frame boundary; 5 ms half radio frame boundary and full 10 ms radio boundary; and 40 ms broadcast channel transmission time interval; and frequency synchronization, which entails acquiring the downlink frequency, so it can be used as a frequency reference for uplink transmission; there are complexities such as determining the bandwidth to be employed for cell acquisition, the physical channels to be employed during cell acquisition, and more importantly the information to be carried by those channels during cell acquisition. While much work has been devoted to addressing each of these issues, the community has so far marginally agreed on a cell acquisition protocol that is fast, reliable, and consumes minimal resources. Therefore, there is a need for cell acquisition protocols with the latter characteristics.